19,938 research outputs found
Evolutionary intelligent agents for e-commerce: Generic preference detection with feature analysis
Product recommendation and preference tracking systems have been adopted extensively in e-commerce businesses. However, the heterogeneity of product attributes results in undesired impediment for an efficient yet personalized e-commerce product brokering. Amid the assortment of product attributes, there are some intrinsic generic attributes having significant relation to a customer’s generic preference. This paper proposes a novel approach in the detection of generic product attributes through feature analysis. The objective is to provide an insight to the understanding of customers’ generic preference. Furthermore, a genetic algorithm is used to find the suitable feature weight set, hence reducing the rate of misclassification. A prototype has been implemented and the experimental results are promising
FPGA-Based Tracklet Approach to Level-1 Track Finding at CMS for the HL-LHC
During the High Luminosity LHC, the CMS detector will need charged particle
tracking at the hardware trigger level to maintain a manageable trigger rate
and achieve its physics goals. The tracklet approach is a track-finding
algorithm based on a road-search algorithm that has been implemented on
commercially available FPGA technology. The tracklet algorithm has achieved
high performance in track-finding and completes tracking within 3.4 s on a
Xilinx Virtex-7 FPGA. An overview of the algorithm and its implementation on an
FPGA is given, results are shown from a demonstrator test stand and system
performance studies are presented.Comment: Submitted to proceedings of Connecting The Dots/Intelligent Trackers
2017, Orsay, Franc
A Case for Redundant Arrays of Hybrid Disks (RAHD)
Hybrid Hard Disk Drive was originally concepted by Samsung, which incorporates a Flash memory in a magnetic disk. The combined ultra-high-density benefits of magnetic storage and the low-power and fast read access of NAND technology inspires us to construct Redundant Arrays of Hybrid Disks (RAHD) to offer a possible alternative to today’s Redundant Arrays of Independent Disks (RAIDs) and/or Massive Arrays of Idle Disks (MAIDs). We first design an internal management system (including Energy-Efficient Control) for hybrid disks. Three traces collected from real systems as well as a synthetic trace are then used to evaluate the RAHD arrays. The trace-driven experimental results show: in the high speed mode, a RAHD outplays the purely-magnetic-disk-based RAIDs by a factor of 2.4–4; in the energy-efficient mode, a RAHD4/5 can save up to 89% of energy at little performance degradationPeer reviewe
Terrestrial planets across space and time
The study of cosmology, galaxy formation and exoplanets has now advanced to a
stage where a cosmic inventory of terrestrial planets may be attempted. By
coupling semi-analytic models of galaxy formation to a recipe that relates the
occurrence of planets to the mass and metallicity of their host stars, we trace
the population of terrestrial planets around both solar-mass (FGK type) and
lower-mass (M dwarf) stars throughout all of cosmic history. We find that the
mean age of terrestrial planets in the local Universe is Gyr for FGK
hosts and Gyr for M dwarfs. We estimate that hot Jupiters have
depleted the population of terrestrial planets around FGK stars by no more than
, and that only of the terrestrial planets at the
current epoch are orbiting stars in a metallicity range for which such planets
have yet to be confirmed. The typical terrestrial planet in the local Universe
is located in a spheroid-dominated galaxy with a total stellar mass comparable
to that of the Milky Way. When looking at the inventory of planets throughout
the whole observable Universe, we argue for a total of and terrestrial planets around FGK and M
stars, respectively. Due to light travel time effects, the terrestrial planets
on our past light cone exhibit a mean age of just Gyr. These
results are discussed in the context of cosmic habitability, the Copernican
principle and searches for extraterrestrial intelligence at cosmological
distances.Comment: 11 pages, 8 figures. v.2: Accepted for publication in ApJ. Some
changes in quantitative results compared to v.1, mainly due to differences in
IMF assumption
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